It's called the one-ring scam. And if you fall for it, it will cost you a lot of money. Here's the scam: You receive a call on your cell phone from area code 473. The caller hangs up after a single ring, hoping you'll call back. And if curiosity gets the better of you and call back, you've been scammed. Forbes reports that while area code 473 appears to be a domestic phone number, it is not. It is actually for the islands of Grenada, Carriacou and Petite Martinique. Even though the area code uses country code 1 like the United States, numbers placed to 473 are international calls -- and can be very pricey. How much? The rate can exceed $20 for the first minute. This isn't the only area code pulling this scam. Others include 242, 246, 264, 268, 284, 345, 441, 473, 649, 664, 758, 767, 784, 809, 829, 849, 868, 876 and 869. So, what can you do to protect yourself?

Do not let curiosity get the better of you. Do not return calls from numbers you do not recognize, no matter what the area code.

Assume the call is not important or is a scam if the caller doesn't leave you a voice mail or text message.

If you fall for the scam, contact your phone provider immediately. You may be able to get the charges waived.